Mr Skeptic

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About Mr Skeptic

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  • Birthday 08/13/1984

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    Dunkirk, NY
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  • Favorite Area of Science
    Physics, Biology
  1. definition of 'life'

    I have a degree in biology, but I don't know what life is either. Each definition has its flaws, especially if we aren't restricting it to biological Earth life. At the end of the day, it is just a definition we make up and things fit it or they don't. But it is very educational to try. To start off, decide which things you want to define as alive or whether you want to restrict your definition. Earth life, viruses (which can't reproduce without a living cell), alien organic life, alien inorganic life, mechanical sentient robots, which of these are alive and which of these are not, or which of these do you want to ignore for the sake of simplicity? These concepts might help: life must at some point be able to reproduce (else it would not exist), there needs to be a boundary between the living thing and its environment (for non-virus Earth life, that is a phospholipid bilayer, much the same thing as a soap bubble but more stable), the ability to maintain homeostasis (though again viruses are an exception).
  2. Reason for 2nd law of thermodynamics and evolution

    Wrong on both counts. Also, how come you were even born, aren't you more organized than a fertilized egg cell and a bunch of food? Once you understand the second law of thermodynamics, you will understand that it is possible for you to have been born.
  3. I think the agreed-upon definition of intelligence was "The ability to solve mental problems." or "The ability to construct a model of a problem and solve it.". The disagreement stems from the fact that there are many kinds of problems with many solutions, and the definition of intelligence does not give any way to measure intelligence. Also, many people are more interested in certain kinds of problems, say concerning abstract concepts rather than things like being able to recognize objects' identities, sizes, and distances given a visual image of them. For example, shooting a basketball through a hoop requires all sorts of calculations, first recognizing what the hoop is, then measuring the distance to it using size comparisons or trigonometry, then if bouncing off the backboard measuring the angle the board is at, then calculating the velocity and direction to throw the ball at given a uniform downward acceleration of g and perhaps also air resistance and the curvature caused by spin, then finally sending signals to hundreds of different muscles to contract and relax in such a way as to throw the ball at the calculated angle and velocity. If also playing basketball, these calculations need to be done in a fraction of a second, and should also consider the odds of making the shot and the actions of nearby players to potentially block your shot or that you might pass the ball to a teammate with better odds. Yet many people would balk at having this be considered intelligence. Similarly, computers can perform millions of calculations in the time we might do one, but they are limited in that their abilities only apply to very specific problems and are completely unable to solve novel problems (that they have not been programed to solve or learn to solve). So a computer's intelligence beats ours by far when it comes to arithmetic, but they can be as dumb as a rock for things we might find simple. While we're on the topic of computers, a measureable definition for intelligence might be the number of calculations per second the entity is capable of. This is a good definition for comparing computers, but for neural networks it seems what people are interested in is the number of synapses (the more synapses the more difficult it would be to construct a computer simulation thereof). Of course calculations per second doesn't actually say much about whether all those calculations help solve a problem, so that isn't really a measure of intelligence but perhaps of complexity or calculating power. Some people also place great value on the ability to learn as an aspect of intelligence. Of course people with amnesia might have a problem with that. More problems occur when we allow the use of the environment in problem-solving. What about people who use pencil and paper/written notes to aid their mental capabilities, or books, or computers, or asking other people? These things might seem like cheating on a test but in reality are how things are done. But then our intelligence would depend not only on our internal state but on what we have access to, which would make it even harder to understand and measure.
  4. Existence Ex Nihilo (NOT Creation Ex Nihilo)

    So if I'm understanding correctly, you propose that there is a machine that can produce work by taking gravitationally condensed clumps of matter and dispersing them through space? This seems rather odd to me; I can easily think of a machine that does the opposite but not one that does what you seem to be proposing. If you don't propose that such a machine can be made, then are we agreed that distributed matter has more useable energy than gravitationally clumped matter, and that gravitational clumping reduces the amount of useable energy?
  5. Existence Ex Nihilo (NOT Creation Ex Nihilo)

    I'm not sure how that follows. Also, you and cosmologists might not be talking about the same sort of creation -- certainly at the time of the BB any information from any previous universe would have been largely destroyed due to the environment, so we could say our universe was created then then even if the matter and energy were there forever. On the other hand, I have heard suggestions that the total energy of the universe is zero due to some sort of negative energy from the expansion of space That's the First Law of Thermodynamics, and in no way conflicts with the second law. Exactly, and in an insulated system the entropy increases -- so says the Second Law of Thermodynamics. Entropy is not destruction of energy, it just means you won't be able to use that energy. Edit: Just to clarify, an example of increasing entropy would be what happens when you mix 1 gram of water with 300 calories of energy with 1 gram of water with 350 calories of energy -- you get 2 grams of water with a total of 650 calories of energy (325 calories each). See how the entropy increased there?
  6. Human Evolution

    Actually, the first species to change the global environment were the first oxygen releasing photosynthetic bacteria. Oxygen is of course a highly toxic substance, so this change caused massive extinctions -- even to this day there are bacteria that can't survive an oxygenated environment, and though we ourselves need oxygen to live the levels of it are tightly controlled and we have all kinds of chemicals to negate the toxicity. On the other hand, that change allowed for terrestrial plants and creatures due to the ozone layer, and for our more improved energy storage where much of the weight is stored outside of our body as atmospheric oxygen, and for easily built fire and the technologies that came from that. I'm just saying that natural selection can't be bypassed, nor evolution negated due to our technological toys, nor that evolution has already been made irrelevant. However, I also think in the future the majority of our genetic change will come from genetic engineering rather than as dictated by mutation and selection. Sorry if I seem rather confusing, I'll be glad to clear up anything that remains murky.
  7. Why should the star have "pointed" to where Jesus was born, or any other location? It would have sufficed for the Magi to have recognized the star as a sign that they should start searching for the King, and been able to recognize Him. It's not as though you can actually point to a particular spot on Earth with a star, what with it rotating and stuff.
  8. UV light helps lots of chemical reactions happen. As such, it would have been very useful to early pre-life and life. But modern life has enzymes for all the reactions we need, and so for the most part any extra chemistry happening in our bodies is going to be harmful. Nevertheless, a few reactions still require UV, such as formation of certain vitamins (Vitamin D for us, plenty of others for plants). Because UV light is generally harmful to life, we have chemicals to block it. Since it also has a lot of energy, there's plenty of chemicals that absorb it to use it as well. So a decent amount of algae in the water will alone absorb plenty of UV. Water also absorbs UV, though not too well, so don't expect clouds nor swimming to protect you from sunburn.
  9. Why? Neurons have a complicated cell shape that is largely responsible for what they do. If much of their function is due from that, why would they also need to be "packed full of" some other control center? If anything impresses me about cell-level intelligence, it would be our immune system.
  10. What equation did you use to calculate the accelerations, and why does your acceleration have the wrong units?
  11. They use cell surface receptors, which set off a chemical signal cascade when they detect something. It's not really stereo, since there are far more than two receptors. It could in theory have a lot of data, but it is communicated largely via a chemical gradient due to the speed of diffusion. Ultimately, it is the DNA and the proteins which read it that are the brain behind everything happening in the cell. However, in many cases the setup from sensing to movement, was set up to occur automatically, before any sensing happened. Not unless you consider the arrangement of receptors, internal receptors, and motor proteins to be the seat of cognition.
  12. Magnetic Power

    Include in your contraption one or more loops of cable, through which you pass electric current. Then your magnet will turn your contraption.
  13. Optics

    Yes the distances will be the same because there is no magnification. And your picture should have had at least two rays, for the top and bottom of the object.
  14. Human Evolution

    Oh, we humans are not helpless without our toys. Well, posting from the US but I meant our species. Even without much intellect, a heavy stick or a long stick (natural objects) combined with our teamwork and cunning are enough to take on any animal. Unlike most animals, we can throw stuff. Even throwing little pebbles is a skill appreciated by the bad-mannered dogs in any country where dogs are allowed to roam free. And that contest grows more unbalanced as technology and intelligence improved. (Also note that all animals require their environment, so it would be quite unfair to pretend we had to do without any of it) Physically, we are also good long-distance runners. We can beat a horse, for example, and rough terrain would tip the balance even more in our favor compared to a horse. We should also be able to beat a cheetah or lion at long distance, those cats may be quick but they overheat easily. You might not appreciate your sweat glands, but few mammals have them. If you go to the tropics, tribes there have little in the way of clothing, often with the children wearing nothing at all -- we don't die of exposure without clothing, not in our home environment. Now throw in our real talents -- language and technology -- then we're real dangerous. Even so, we've always suffered from famine, disease, and violence. Even if we eliminate these, we will still have to compete with other humans. Though I believe if we let genetic engineering grow to become a proper field, natural evolution will become nearly irrelevant to us.
  15. Limits

    I don't know if this is a kosher way to do it, but the simplest way would be to add a constant to your square root to make it a perfect square. But then you have to prove adding the constant doesn't change the answer at the limit.